proneness

noun4

1. •
   The quality or state of being prone, or of bending downward.

   • The proneness of animals is opposed to the erect posture of human beings.
2. •
   Inclination of mind, heart, or temper; propension; disposition.
3. •
   The state of lying with the face down.
4. •
   (old-fashioned) Descent; declivity.